Current and future generation semiconductor memory applications utilize very high memory I/O speeds to read and write data. Examples of such semiconductor memory include dynamic random access memory (DRAM) and synchronous dynamic random access memory (SDRAM), as well as many others.
The demand for high memory I/O speeds is particularly true in graphics memory, such as current and future generation GDDR5/GDDR5X specifications. Graphics memories are designed for applications requiring high bandwidths and high memory I/O speeds, for example, in excess of 8 Gbps. The high memory I/O speeds, however, consume more power than compared to lower memory I/O speeds. While many applications of such memory demand high memory I/O speeds, other applications may prioritize lower power consumption and accept lower memory I/O speeds.
It may be desirable for a semiconductor memory to be operated at various clock frequencies to provide different memory I/O speeds.